Diet Debate - Does Any Diet Really Work

Posted Nov 21 2008 8:41pm

A study published in The New England Journal of Medicine last week says ," A low-fat diet is not the only safe and effective way to shed pounds, according to a new study that shows low-carbohydrate and Mediterranean diets also result in weight loss, and appear to also offer other health benefits."

Iris Shai , RD, PhD, and researchers from Harvard University and other institutions assigned 322 moderately obese men and women, average age 52 and with a body mass index (BMI) of 31, to one of three diets.

The low-fat diet was based on American Heart Association guidelines. In the group following this diet, women ate 1,500 calories a day and men ate 1,800 calories. They took in just 30% of calories from fat, including 10% saturated fat, and were limited to 300 milligrams of cholesterol a day. (A large egg has about 200 milligrams of cholesterol). They focused on eating low-fat grains, vegetables, legumes, and fruits -- and reduced intake of extra fats, sweets, and fatty snacks.

The Mediterranean diet was based on the writings of Walter Willet from Harvard Medical School. In the group following this diet, women consumed 1,500 calories a day and men consumed 1,800 calories. The goal was to eat no more than 35% of calories from fat, and the main sources of added fat were olive oil and a few nuts a day. The diet was rich in vegetables and low in red meat, with fish and chicken replacing beef and lamb.

The low-carb diet was based on the Atkins plan. In this group, calories weren't restricted. These participants were told to eat about 20 grams of carbs a day (about the amount in two slices of bread) for two months, and then increase it to no more than 120 grams a day. They focused on vegetarian sources of fat and protein and avoided foods with trans fat.